IMPLEMENTATION OF PARALLEL ADC & COMPARISON WITH OTHER ADCs

Abstract

In nay dissertation I implemented parallel ADC using CMOS technology using Tanner Tool. for Simulation. Which is With S-Edit, Tanner Tools brings to the front-end design capture the ease-of-use and design productivity for which Tanner Tools are known. It is tightly integrated, with Tanner's T-Spice simulation and verification tool. Parallel analog-to-digital converters, also known as flash ADCs, are the fastest way to convert an analog signal to a digital signal. Parallel ADCs are ideal for applications requiring very large bandwidth, however, they typically consume more power than other ADC architectures and are generally limited to 8-bits resolution. Parallel ADCs are made by cascading high-speed comparators. Each comparator represents 1 LSB, and the output code can be determined in one compare cycle. This dissertation will also talk about flash converters vs. other converter types. An ADC is an electronic device that converts an input analog voltage (or current) to a digital number. The digital output may be using different coding .schemes, such as binary and two's complement binary and I use the binary schemes. The resolution of the converter indicates the number of discrete values it can produce over the range of voltage values. The values are usually stored electronically in binary form, so the resolution is usually expressed in bits. And I implement 3bits resolution ADC. An ADC has several sources of errors. Quantization error and non-linearity is intrinsic to any analog-to-digital conversion. There is also a so-called aperture error which is due to a clock jitter and reveals when digitizing a signal .These errors are measured in a unit called the LSB, which is an abbreviation for least significant bit. Most converters sample with 6 to 24 bits of resolution, and produce fewer than I megasample per-second. It is rare to get more than 24 bits of resolution. Mega- and gigasample converters are available, though. Megasample converters are required in digital video cameras, video capture cards, and TV tuner cards to convert full-speed analog video to digital video files. Commercial converters usually have ±0.5 to ±1.5 LSB in error in their output. In many cases the most expensive part of an integrated circuit is the pins, because they make the package larger, and each pin has to be connected to the integrated circuit's silicon.